Paint Calculator
Work out how much paint you need for a room, based on coats and coverage.
Need More Jobs?
You know what each job is worth. Now get more of them. MCC Growth helps trade and local service businesses improve their visibility on Google and generate more enquiries from people already searching for their services.
Work out exactly how much paint to buy
Enter the room's total wall length and height, subtract doors and windows, set your number of coats and the coverage of your chosen paint, and get a litre and gallon estimate.
How to use it
- Enter the total perimeter (all walls added together) and the wall height.
- Enter how many doors and windows to subtract (standard sizes are used automatically).
- Set the number of coats and the coverage per litre from the paint tin.
The formula
Worked example
An 18m perimeter room at 2.4m high has 43.2 m² of wall. Subtracting 1 door and 2 windows (4.6 m²) leaves 38.6 m² to paint. At 2 coats and 10 m²/litre coverage, you'll need about 7.8 litres — round up to 8.
Frequently Asked Questions
Does this account for ceilings?
No — this calculates wall area only. Measure ceiling area separately (length × width) if you're painting it too.
What size does it assume for doors and windows?
A standard door is assumed at 1.6 m² and a standard window at 1.5 m². For non-standard openings, adjust the door/window count or subtract the difference manually.